高电压钴酸锂电池电解液研究进展

Research progress of functional electrolyte for high-voltage LiCoO_(2) battery

钴酸锂(LiCoO_(2))具有高压实密度、高体积能量密度、优异的导电性能以及使用寿命长等优点,占据消费类电子产品的主要市场。LiCoO_(2)材料的理论比容量高达274 mAh/g,而其在4.2 V的电压下比容量仅为140 mAh/g。随着消费类电子产品对高能量密度的迫切需求,提高LiCoO_(2)材料工作电压成为当前研究的热点。材料改性和功能电解液设计是实现高电压LiCoO_(2)电池的主要途径。相比较而言,功能电解液设计是一种高效且经济的途径,对高能量密度LiCoO_(2)电池的研发具有重要意义。从高压有机溶剂、高压添加剂以及局部高浓度电解液三个方面入手,综述了近年来国内外高电压LiCoO_(2)电池电解液的研究进展,重点阐述了电解液溶剂的氧化窗口、电极与电解液界面反应以及锂离子溶剂化结构对高电压LiCoO_(2)电池性能的影响。最后,对高电压LiCoO_(2)电池电解液的发展前景作出了总结和展望。

Lithium cobalt oxide(LiCoO_(2))has the advantages of high compaction density,high volume energy density,excellent conductivity and long service life,which makes it still occupy the main market of consumer electronic products.The theoretical specific capacity of LiCoO_(2)material is as high as 274 mAh/g,while its capacity at a voltage of 4.2 V is only 140 mAh/g.As the increasing demand for high energy density of lithium-ion batteries,elevating the operating voltage becomes the direct route to enhancing the energy density of LiCoO_(2) batteries.Correspondingly,great attention has been paid to develop high voltage electrolyte with the advantages of high efficient and economical for practical application.Herein,the recent progress of functional electrolyte for high voltage LiCoO_(2) batteries has been reviewed elaborately,which could be divided to high voltage organic solvent,high voltage additive and localized high concentration electrolyte.The effect of electrochemical stability window,the film forming ability and the solvation structure of electrolyte on the performance of high voltage LiCoO_(2) batteries are discussed systematically.Finally,the further development of high voltage electrolytes for LiCoO_(2) cathode is prospected accordingly.